An Effective Color Quantization Method Using Octree-Based Self-Organizing Maps

Algorithm 1

Learning algorithm of octree-based SOM color quantization.

Require: image as a vector of pixels, number of neurons .

Ensure: weight

  Build octree on image and prune the nodes until nodes remain.

   value of pruned nodes

  loop counter

  repeat

      generate subset of training pixels

      number of training data

     adjusted learning rate for winner node

     /100

    for    to    do

      Determine the winner node

      Update weight of the winner and its neighbors

    end for

  until weights converged